What does your coffee taste like?

Pick the symptom. Bitter usually means over-extracted, sour means under-extracted, and weak means the ratio is off. Fix one variable at a time.

All the fix guides

• Bitter Espresso: Why Shots Turn Harsh and How to Fix It

  Bitter espresso usually means over-extraction: the grind is too fine, the shot runs too long, or the yield is too high. Fix the timing first.

• Espresso Channeling: How to Spot It and Stop It

  Espresso channeling is water punching a fast path through the puck. It tastes sour and harsh at once, and puck prep fixes it, not grind.

• Over Extracted Coffee vs Under Extracted: The Fix Chart

  Over extracted coffee tastes harsh and drying, under extracted tastes sharp and thin. Grind, heat, time and ratio move the cup either way.

• Sour Coffee: Why It Happens and How to Fix It Fast

  Sour coffee is under-extracted: grind too coarse, water too cool, or brew too short. Push extraction further, one small step at a time.

• Why Is My Coffee Bitter? Causes and the Fastest Fixes

  Bitter coffee is almost always over-extracted: grind too fine, water too hot, or brewed too long. Change one variable at a time.

The one rule of troubleshooting

Change one thing between brews. If you change the grind, the dose and the temperature at once, a better cup teaches you nothing. The usual order: get the dose right first, then adjust grind, then temperature, then time. Most bad coffee is fixed at step one or two.